数学学霸看过来·几道初三的数学题·在线等·谢谢！ 数学学霸看过来呀：数学遇到不会的题目怎么办，初中。女生。
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a+b+c=3……①4a-2b+c=3……②
9a+3b+c=13……③
②-①得：3a-3b=0，a=b，
③-②得：5a+5b=10，∴a=b=1，
∴c=1。
②方程两边都乘以2(X+2)(X-2)得：
4(X-2)-2(X-1)(X+2)=X^2-4，
4X-8-2X^2-2X+4=X^2-4
3X^2+2X=0
X=0或X=-2/3，
经检验都是原方程的根。
⑶Δ=(m+1)^2-4m=(m-1)^2≥0，
∴抛物线与X轴有交点。
对称轴X=(m+1)/2=-2，
m=-5,
∴抛物线：Y=X^2+4X-5，
绛旓細4a-2b+c=3鈥︹︹憽 9a+3b+c=13鈥︹︹憿 鈶-鈶犲緱锛3a-3b=0锛宎=b锛屸憿-鈶″緱锛5a+5b=10锛屸埓a=b=1锛屸埓c=1銆傗憽鏂圭▼涓よ竟閮戒箻浠2(X+2)(X-2)寰楋細4(X-2)-2(X-1)(X+2)=X^2-4锛4X-8-2X^2-2X+4=X^2-4 3X^2+2X=0 X=0鎴朮=-2/3锛岀粡妫楠岄兘鏄師鏂圭▼鐨勬牴銆傗懚螖=(m+1)...
绛旓細11銆亁+2=330梅15锛12銆亁=0鎴杧=2锛13銆乵<0.5锛14銆乲=2.25锛15銆2銆3锛16銆亁=6锛17銆1锛18銆-7
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